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(CNN)A former top adviser to President Richard Nixon said Saturday that while he doesn't think tapes of conversations between President Donald Trump and ex-FBI chief James Comey exist, a "taping device" should always be on hand in the Oval Office.

"The President of the United States needs a taping device in the Oval Office," Buchanan said. "If you've got, for example ... the Russians, and what did they say about Syria and Iran and what did they say about Afghanistan? I mean, you want evidence of what they said, and they would expect you would be taping them."

But what about Buchanan's infamous advice to Nixon as Watergate unfolded to "burn the tapes"? Would he repeat it now to Trump? (Note: The Presidential Recordings and Materials Preservation Act of 1974 says tapes like the ones Nixon recorded are presidential records that must be preserved in federal archives.)

"No, if he's made them," replied Buchanan. "Don't you want a tape recording and don't you want a record of that, that you can look over and say, what exactly did they commit to, and what didn't they commit to?" he said.

"Yes," Smerconish replied. "But not between the FBI director and the President."